Carburetor



A ril 4, 1950 G. c. FRICKE ETAL CARBURETOR Filed Nov. 8, 1946 I ll 0 Mir/ma; 620 63 fk/C/(L' E0559) W JZOA E ATTORNEY Patented Apr. 4, 1950 Guy 0. Fricke, Pleasantrldge, and Robert W. I Sloane, Detroit, Mich, assignors to Bendix Aviation Corporation, South Bend, Ind., a corporation of Delaware Application November a, 1946, Serial No. 708,842 4 Claims. (Cl. 137-104) The present invention relates to float type carburetors for internal combustion engines and the like and more particularly to a fuel float, anti inlet valve construction for the aforesaid carburetors.

It is known that in conventional float type carburetors, engine vibration and road jarring transmitted through the vehicle to the carburetor may cause the float to oscillate vertically even though the fuel is at a level normally suflicient to maintain the float'at its uppermost position and the fuel valve closed. Inasmuch as the conventional carburetors are generally provided with a rigid float lever and valve engaging arm, as well as a nonyieldable valve construction, any oscillation of the float when the fuel in the bowl is at full level causes successive momentary openings of the fuel valve and a consequent flow of fuel into the bowl. when the engine is consuming fuel at a low rate, as at idling or slow speed, the opening of the fuel valve under the influence of the engine vibration or road jarring permits fuel to enter the fuel bowl at a greater rate than it is being consumed, thus causing excess fuel to spill from the discharge jet into the induction passage or to overflow the fuel bowl.- It is therefore one of the principal objects of the present invention to provide, in a float type carburetor for an internal combustion engine, a fuel valve control.

-mechanism which is unaffected in its operation by engine vibration or road jarring transmitted to said carburetor.

Another object of the present invention is to provide, in a float type carburetor for an internal combustion engine, a linkage between the float and the fuel inlet valve which will not transmit engine vibration or road jarring from the float to the fuel inlet valve.

Another object is to provide in a carburetor a .resilient linkage between a float and a valve which is capable of maintaining the valve in its closed position irrespective of vibration transmitted to said float.

Still another object of the invention is to provide a valve control mechanism for a carburetor which is unaffected in its operation by vibration of the carburetor.

A further object is to provide a compound float lever for controlling a fuel inlet valve, which can be readily assembled in operating position in a carburetor and thereafter easily serviced and the parts thereof readily replaced in the fleld.

Additional objects and advantages of the present invention 'will appear from the following cleecription and accompanying drawings wherein a 65 tem is only P tially Show specific embodiment of our invention is disclosed. The linkage between the float and valve is not limited to the particular embodiment disclosed herein nor to a linkage in a carburetor for an internal combustion engine, but is understood to be available in many carburetor constructions in which a float for controlling a valve is subjected to extraneous vibrations and jarring adversely affecting control of the valve by said float.

Figure 1 is a vertical cross section of a conventional carburetor showing several of the principal features thereof in conjunction with the present invention.

Figure 2 is an isometric view of the linkage between the fuel float and fuel valve showing the parts thereof in their assembled positions, together with a portion of the float.

Figure 3 is an isometric view of a float lever forming an element in the linkage shown in Figure 2.

Figure 4 is an isometric view of the valve engaging arm of the linkage shown in Figure 2.

The present invention may be readily understood by referring to the drawings in which Figure 1 illustrates a conventional downdraft single barrel carburetor for an internal combustion engine, wherein numeral I0 designates a main body, I! an air horn, It a throttle body and It a fuel bowl or float chamber having a float l8 and fuel inlet generally shown at 20 mounted therein. The

' main body It is secured at the air inlet end thereof to air horn l2 and at the air outlet end to throttle body it and contains a large venturi 22, small venturi 24 concentrically located in respect to said large venturi and a fuel discharge jet 26 connecting fuel bowl It with the throat of the small venturi. The small venturi 24 is held in place by fln 28 which is preferably integrally.

connected to the said venturi and to the side wall of main...body In. The main discharge jet which The accelerating pump and power enrichment jet usually included in conventional carburetors are not shown in the drawings and the idle syssaid system being 48 for suitable bolts are provided at the mixture discharge end of the throttle body.

The flow of fuel through inlet 20 into float chamber i6 is controlled by float I8 through -'linkage"58 in accordance with the quantity of fuel in said chamber, said linkage including a compound lever 52, pivoted at one end, for supporting float l8,'in combination with a fuel valve stem 54 adapted to abut against and to be actuated by said compound leved. A fuel'valve 55 which is directly controlled by stem 54 regulates the flow of fuel through orifice B and is preferably joined integrally with said stem. The float l8 is'mounted on a rigid hinge 51 of compound lever 52. and is secured thereto preferably by brazing or soldering, although any other suitable joining means may be used. Hinge 51 is mounted I on pin 58 and rotatably secured thereto by rolled portions 58 and 82 formed-in the margin of the lever on the end opposite the float, said rolled portions being formed in spaced relation to one another to provide slot 64 between the two portions. A longitudinal stiffening rib 68 is provided along each side of hinge 51 to give rigidity to said hinge between float I 8 and pin 58. Pin 58 on which hinge 51 is mounted is secured in place adjacent fuel inlet 28 by a bifurcated bracket 88 depending from the top 10 of the float chamber.

A resilient U-shaped lever or hairpin spring 12 operates in conjunction with hinge 51 and is provided with a rolled portion 14 at the end of prong 15 to form an eye for rotatably mounting said lever on pin 58 in slot 64. In the assembled position said prong extends from pin 58 along the lower side of hinge 51 through hole 16 to the top side of said hinge, and the portion of said prong 15 adjacent the U-shaped bend 11 normally rests on the top side of hinge 51 directly above float l8.

Valve stem 54 is slidably received in sleeve 18 and rests on prong 18 of lever 12 which is so positioned in respect to inlet that any oscillating movement of said hinge when the fuel bowl is below full level causes stem 54 and valve 55 to reciprocate in sleeve 18 and to open and close inlet orifice 56. Inthe arrangement and construction shown inthe drawings, prong 19 of the resilient lever 12 will be pressed downwardly toward hinge 51 when the fuel is at full level in bowl l5 and the float is in its uppermost position, yieldably holding valve 55 in its closed position. Some of the force to which prong 19 is subjected is transmitted through the U-shaped bend to prong 15 between rolled portion 14 and the point at which prong 15 contacts the top surface of hinge 51, thus giving greater resiliency to lever 12 and making it more effective in dampening the vibration transmitted to the carburetor float.

During the operation of the engine when the fuel in the fuel bowl is appreciably below full level, vibration of the carburetor and the oscillation of the float resulting therefrom have no significant effect on the control of the fuel by the float, but as the quantity of the fuel required by the engine diminishes and the fuel in the bowl approaches full level, any vibration or oscillation causing the valve to open and admit excess fuel raises hinge 51 and lever 12 and increases the force of lever 12 urging valve 55 to its closed of hinge 51, and then'prong 15 is slipped through hole 16 to a position such that rolled portion 14 aligns in slot 84 with rolled portions 80 and 82 of hinge 51. While lever 12 is held in this position, pin 58 is slipped axially through said rolled portions and the ends of the pin are secured in place in the bifurcated bracket 58 adjacent inlet 28. With the lever 12 in this position, prong 18 engages the lower end of valve stem 54 and retains said stern in operative position in sleeve 18. A laterally projecting lug 1| cooperates with 9. lug (not shown) on bracket 68 to prevent said hinge from dropping down so low that valve stem 54 will become dislodged from sleeve 18. It is apparent that the present construction may be easily serviced in the field, and lever 12 which is subjected to incessant vibration during the operation of the engine and consequently may break, may be readily replaced with the removal of a minimum number of parts from the carany manner to the other parts comprising the linkage between the float and fuel inlet valve, it can be constructed of any material having suitable resiliency. Further, after said lever has been formed and properly tempered, it is not subjected to any heat, such as that of a joining operation, which might draw the temper from lever 12 or distort either said lever or hinge 51.

Although only one specific arrangement of the present fuel inlet control mechanism has been given herein, it will be understood that variations therein may be made without departing from the scope of the invention as defined in the appended claims. i

We claim:

1. A compound leverfor a fuel float compris a control member of a fuel inlet valve.

2. A compound float lever for minimizing the effect of vibration on the control of fuel by a float comprising a rigid hinge adapted to be pivoted at one end and to receive a float at the other end, said hinge having a hole therethrough, and

(5 a resilient hairpin lever one prong of which being 5 adapted to extend through said hole and to .be pivoted at a point in common with the pivot 01 said hinge and the other prong of which being adapted to engage a control member of a fuel inlet valve.

3. In a carburetor float assembly adapted to minimize the efiect of vibration on the control of fuel by afloat, the combination comprising a hinge having one end adapted to receive a float and having a means on the opposite end for piv-' oting said hinge, said hinge having a centrally located hole, a pin for said means, and a resilient hairpin lever having one prong extended through said hole and pivoted on said pin and the other prong being adapted to engage a control member of a fuel inlet valve. 1

4. A compound float lever for minimizing the eflectxoi vibration on a fluid control valve by a float, comprising a hinge adapted to be pivoted at one end and to receive a float at the other end, said hinge having a hole therein spaced from the pivoted end, and a resilient lever turned upon itself extending through said hole and adapted to be pivoted adjacent the pivoted end of said hinge and to engage an actuating member of the control valve.

GUY C. FRICKE. ROBERT W. SLOANE.

REFERENCES CITED The following references are of record in the file of this patent:

' UNITED STATES PATENTS 

